Lubricating oil



Patented Sept. 2, 1941 UNlTED sTATEsfriRrE T OFFICE.

LUBBICATING OIL Ernest Segessemann, Newark, N. J., assignor to NationalOil Products Company, Harrison, N. J a corporation of New Jersey NoDrawing. Application June 18, 1938, Serial No. 214,581

13 Claims. (01. 252-46) The invention relates in general to lubricantsand more particularly to sulfur-containing lubricants adapted for use ascutting oils and extreme pressure lubricants and to correlatedimprovements in the process of producing such lubricants.

In the fabrication of metals into stock mate- I rials, articles, machineelements, etc., by methods involving cutting, grooving, turning,milling, brooching, boring, hobbin'g, gear cutting, grinding, stamping,drawing, etc., operations, frictional forces are created which causeoverheating and accelerated dulling of the cutting tools, dies, etc.,used in such operations. Moreover, the metals being subjected to theaforementioned /operations become overheated, thereby deleteriouslyaffecting the uniformity and quality of the finished products.

In an attempt to combat these difliculties, it has been proposed toemploy various oils and compositions containing oils for cooling andlubricating both the cutting tools, dies,-etc., as well as the metalbeing worked upon. In general, there are four main types of cuttingoils, to wit, (1) straight mineral oil, (2) mineral lard oil,

, (3) sulfurized mineral or mineral lard oil and (4) soluble oils(emulsifiable with water). The present invention is directed in part tothe socalled sulfurized cutting oils which may be used straight or inthe emulsified form.

The two primary functions of a cutting oil in the metal working arts arecooling and lubricating'which in turn serve to increase production andyield products having a better surface finish. An ideal cutting oilshould be endowed with the following characteristics: (1) high specificheat, (2) good wetting and spreading power, (3) adherence to the;essential elements and a adequate flow; (5) stability, (6) free of firehazards, ('7) non-corrosive and. (8 non-injurious to health. While manysoluble cutting oils have been proposed and preparechnone of these haveeven remotely satisfied the foregoing characteristics.

The invention is further directed to the socalled extreme pressurelubricants. In the lubrication of moving surfaces, such astransmissions, hypoid gears, etc., it is of prime importance to employan oil having a high film strength 'to withstand the great pressurebetween the moving surfaces. While various'E. P. lubricants have beenused to varying degrees ofsuccess, a-constant need for improvementexists.

good film strength, (4) a viscosity permitting fore been prepared eitherby incorporating sulfur into mineral oils in the form of a finelydivided suspension or by compounding mineral lubricating oils withsulfur-containing fatty oils, such as sulfurized lard oil, cottonseedoil, etc.v All thesecompounds, while useful, often lack the stabilityrequired under storage and working conditions. The products. containingfree sulfur show a tendency towards sedimentation and the comebacteria-infected and develop into carriers of disease among which skinirritations are the most prevalent.

The general object of the invention is toobviate the foregoing and otherdisadvantages.

A specific object of the invention is to provide an improvedsulfur-containing lubricant characterized by being stable, non-corrosiveand free from bacteria infection.

Another object of the invention is to provide an improved process ofproducing cutting oils and E. P. lubricants in general.

A furtherobject of the invention is to provide an emulsifiable cuttingoil of enhanced stability and lubricating value.

Other objects of the invention will impart be obvious and will in partappear hereinafter.

It has now beenfound that a satisfactory sulfur base, which lends itselfreadily to the preparation of sulfurized mineral oils, can be made,according to the invention, by incorporating sulfur into unsaturatedfatty alcohols. These sulfurized alcohols are soluble in all proportionswith the hydrocarbon oils commonly used in formulating cutting oils andextreme pressure lubricants.

- The resulting sulfur-containing mineral oils exhibit a markedstability on storage and under rigorous working conditions. They arefree from any tendency to develop rancidity, sludge or gum formation.Due to the absence of rancid- Sulfur-containing lubricating oils haveheretoity, the hazard arising from bacterial impurities are greatlylessened. The novel lubricating oil may also have an emulsifierblendedtherewith "has exhibit a marked olliness" subjecting theto-produce an emulsified lubricant particularly adapted for use as acutting oil.

Theinvention accordingly comprises the several steps and relation of oneor more of such steps with respect to each of the others, and'acomposition ofmatter g the characteristics, properties and relation ofcomponents, all of which will be exemplified in the following detaileddisclosure, and the scope of the invention will be indicated in theclaims.

Cutting oils prepared according to ,the invention from the sulfurizedunsaturated fatty alcoand ability to penetrate into the smallestcrevices of the work. Their high lubricating quality permits smoothcutting and cooling of the machined parts, enabling operations at highturning speeds. Their high stability towards decomposition permitsreconditioning or reclaiming without deterioration over a longer periodof time than in the case of lubricants containing fatty oils.

Extreme pressure lubricants prepared according to the invention from thesulfurized unsaturated fatty alcohols have been found to be particularlyuseful in transmissions and in hypoid gears where their freedom from gumand sludge formation during use and their marked film strength enablesthem to maintain a high loadcarrying capacity over extended periods ofservice hours and under extreme pressure conditions.

The sulfur may be incorporated into the unsaturated fatty alcoholsbyheating the unsaturated alcohol with the required amount of sulfur ata temperature usually ranging between 130-180 C. or the sulfur and thealcohol may be dissolved in a suitable solvent, such as xylene ortoluene and heated at the boiling point of the solvent until all thesulfur has combined with the alcohol. During the operation smallquantities of hydrogen sulfide are evolved and in order to free thefinished product of the last traces thereof a stream of air may bepassed through the liquid. Y

Any suitable unsaturated aliphatic primary, secondary or tertiaryalcohols with normal or ramified carbon chains, may be used according tothe present invention having 8 or more carbon atoms which are generallyreferred to as fatty alcohols. Examples of such alcohol include, interalia, oleyl alcohol, linoleyl alcohol, ricinoleyl alcohol, hexadecenylalcohol, undecylenic alcohol, erucyl alcohol or unsaturated alcohols,such as are obtainable by reducing unsaturated fatty acid esters. Therealso come into consideration the alcohols occurring in certain waxes,for example, in sperm oil or in Dbgling's oil wherein the unsaturatedalcohols are obtained by saponiflcation and subsequent extraction ordistillation thereof. It is also possible to start with unsaturatedalcohols which are produced by treating chlorinated parafiins withalkalies, whereby double bonds are produced in consequence of theelimination of HCl.

The sulfurized unsaturated alcohols may also be produced from saturatedfatty alcohols by latter to the action of sulfur at high temperatures,whereby dehydrogenation takes place with the evolution of Has. Theresulting unsaturated alcohols may then be treated withadditional sulfurto bring about sulfurization thereof. Sufficient sulfur may be added tothe saturated fatty alcohols at the outset to as sulfurization event,

cause dehydrogenation as well in a continuous operation. In any to beconstrued in a limiting sense, all parts are used as the startingmaterial, the end product will comprise a sulfurired unsaturated fattyalcohol. The expression sulfurized unsaturated fatty alcohols is usedherein to connote the end product produced by the chemical reaction ofsulfur with an unsaturated fatty alcohol, which product may becompletely saturated or only partially saturated depending upon theextent of sulfurization.

The sulfurized alcohols thus obtained are clear, oily liquids, free fromsludge or sediment and are miscible with hydrocarbon oils in allproportions. Their sulfur content may range from 2 to 25%. The cuttingoils or extreme pressure lubricants are prepared by blending with asuitable lubricating oil a proper portion of the sulfur base to give thedesired sulfur content in the finished product.

To render the lubricant emulsiflable, any suitable emulsifying agent maybe blended therewith, such for example, as sulfonated sperm oil, mineraloil sulfonates (mahogany soaps), fatty acid soaps, etc. Theemulsifierandlor the other ingredients may be proportioned to yield anemul- :ion of either the water-in-oil or the oil-in-water For a fullerunderstanding of the nature and objects of the invention, referenceshould be had to the following examples which are given merely tofurther illustrate the invention and are not given being by weight:

Example I In an open vessel provided with mechanical agitation, 200parts of alcohols obtained by the hydrolysis of sperm oil are heated toabout 130 C. and parts of flowers of sulfur are then added in smallportions. at frequent intervals. when all the sulfur has been added. thetemperature is raised and maintained at about 160 C. for four hours. Atthe end of this period' all the sulfur has combined with the alcohol.when cooled, the oil is clear, liquid and free from any whethersaturated or unsaturated fatty alcohols 76 sludge or free sulfur. Itssulfur content ranges from about 18 to 19%.

A cutting oil was prepared by blending one part of the sulfur baseobtained in the above example with flve parts 'of a pale lubricating oilhaving a Saybolt viscosity of 80 seconds at F. The blend has a sulfurcontent of 3%. a lightcolored oil, free from sludge and was found to behighly satisfactory for threading joperations on atl'le tlypes of steel,including stainless and nickel s e s. I

This product may be rendered water-dispersible by adding thereto .5parts of mahogany soaps or sulfonated sperm oil.

Example II reflux condenser are placed 220' parts of xylene and 43 partsof stick sulfur. The xylene is heated to its boiling temperature untilall the sulfur has dissolved. 200 parts of alcohols obtained from thesaponiflcation of sperm oil are then added in a thin stream and slowenough so that the nlene is kept boiling continually. Refluxing iscontinued for'seven hours or until a sample of the mixture does notprecipitate any free sulfur upon cooling. The xylene is then distilledoil under reduced pressure. During or after the distillation, a streamof air is allowed to pass through the liquid for the purpose of freeingit of the last traces of hydrogen sulfide. The sulfur content of theproduct tests from about 16% to 17%.

viscosity of 150 seconds 100 F.

Example Hi In a closed vessel provided with a water-cooled refluxcondenser 65 parts of stick sulfur and 220 parts of xylene are boileduntil the largest portion of the sulfur has dissolved. 200 parts ofoleyl alcohol are then added in a thin stream and at 'such a rate thatthe xylene does not cease boiling. The boiling is continued for 8 hours,at the end of which period the sulfur has completely combined with thealcohol. The xylene is then distilled oil. under atmospheric pressureand air is blown through the liquid until it is entirely free fromobjectionable odors. The sulfurized oleyl alcohol obtained according tothe foregoing procedure contains from 23 to 24% of sulfur. 'I'he basemay be blended with lubricating oils of such vlscosities and in suchproportions as to obtain cutting oils or high pressure lubricants of thedesired properties.

While the use of flowers of sulfur and stick sulfur has been suggested,other forms of sulfur may also be used such as colloidal sulfur and thelike.

Since certain changes in carrying out the above process and certainmodifications in the composition which embody the invention may be madewithout departing from its scope, it is intended that all mattercontained in the above description shall be interpreted as illustrativelimiting sense. D

It is also to be understood that the following claims' are intended tocover all the generic and specific features of the invention hereindescribed and all statements of the scope of the invention, which as amatter of language might be said to fall therebetween; and that they areintended to be inclusive in scope and not exclusive, in that if desired,other materials may be added to my novel composition of matter hereinclaimed withg and not in a 3. out departing from'th'e spirit of theinvention. Particularly it is to be understood that in said claims,ingredients or components recited in the singular are intended toinclude compatible mixtures of said ingredients wherever the sensepermits.

Having described my invention, what I claim as new and desire to secureby Letters Patent is:

1. A new composition of matter comprising a sulfurized unsaturated fattyalcohol. r

2. As a new composition of matter, a sulfur carrier for lubricantscomprising a sulfurized unsaturated aliphatic alcohol having at least 8carbon atoms.

3. As a new composition of matter, a sulfur carrier for lubricantscomprising sulfurized sperm alcohols.

4. As a new composition of matter, a sulfur carrier for lubricantscomprising sulfurized oleyl alcohol.

5. A lubricant comprising a sulfurized unsaturated fatty alcohol and amineral oil.

6. A lubricant comprising sulfurized sperm alcohols and a mineral oil.

'7. A lubricant comprising sulfurized oleyl alecho] and a mineral oil. 4

8. An emulsiflable cutting oil comprising a sulfurizedunsaturated fattyalcohol, a mineral oil and an emulsifying agent.

9. An emulsiflable'cutting oil comprising sulfurized sperm alcohols, amineral, oil and an emulsifying agent.

10. An emulsiflable cutting oil comprising a sulfurized oleyl alcohol, amineral oil and an emulsifying agent. 11. An aqueous emulsion adaptedfor use as a cutting 011 comprising a sulfurized unsaturated fattyalcohol, a mineral oil and an emulsii'm agent.

12. A new composition of matter comprising I sulfurized sperm alcohols.

13. A new composition of matter comprising sulfurized oleyl alcohol. I

ERNEST SEGEBSEMANN.

